Grinding machine



Jay. 20, 1931. H. s. MILLER GRINDING MACHINE Original Filed Jan. 26, 1926 2 Sheets-Sheet 1 Zlwuwntoz flaiay JHiZZez.

Jan. 20, 1931. G2M1LLER 1,789,499

GRINDING momma Original Filed Jan. 26. 1926 2 Sheets-Sheet 2 awn;

Patented an. 20, i

- UNITE Sir-Art s HARRYG. MIL ER, or DE VER; coIioaAno, ASSIGNOR To MILLER SERVICE -'.rooL -co.,

g i,789,49t'

;PATE-NT? OFFICE; :1 2

. or MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN GRInnrNG MACHINE Application filed-January 2e, IBZGLSefial -Nmi 83,827. Renewed June '13, 1930. v

This invention relates to improvements in grinding machines. I i

It is the object of this invention to'produce a simple and inexpensive machine for grind- -5 ing valve tappets, shims and'slmilar articles in a convenient manner and'with great accuracy. a 1

The invention, briefly described, consists of a base to the upper surface ofwhich a motor is secured. A bracket is also secured to the base and carries a grinding disk that is connected with the motor by means of belts in such a manner that it will be rotated by the motor. Anarm or support is mounted for oscillation about an axisthatlies below the axis of the grinding disk and in the plane of rotation of the disk. 7

' end of the oscillatory arm'is a turret head that can be rotated about' an axis which is perpendicular to the axis of-the arm; this turret headhas a hollowcylinclrical sleeve to 1 which the tappet, which is to'be ground;- s

secured and to which the chuck for holding the shims may also be secured. Means have I also been provided for adjusting the fosciL' latory arm towards and away fromthe grinding disk andfor limiting the extent of: the

oscillation. I

Having thus briefly explainedmy invention, I shallnowproceed todescrlbe the same in detail, reference for this purpose being had to the accompanying drawings in which the invention has been illustrated and in which:

Fig. 1 is "a top plan View of the machine;

Fig. 2 is an elevation looking in the direction of arrows 2 -2, Fig. 1,; portions being shown in section or broken away so as to'better disclose the construction; F 3 is a sectiontaken on'line 3+3; Fig. Fig. 4 is a section taken on line 1 4, Fig.1; i V Fig. 5 is alongitudinal section oft-he rotatable sleeve; I i

'Fig. G is a fragmentary section taken on line 44,1Fig. 1, showing. a magnetic chunk;

: tating thescrew 18, the shaft 20 may be'movsubstituted for the tappet; and, i r

w F 1g. 7. is a view of the face of the chuck, two shims having been indicated byldotted Secured to the upper lines as "being in position onthe face of the r In thedrawings numeral 5 designatesthe base upon which is mounted and secured'an' .5

electric motor 6. Alsojmounted upon the base is a frame member or bracket'7 which extends upwardly above the motor and in whichis journalled the shaft 8 upon'which is y v mounted, so as to rotate therewith, a grindmg wheel 9 of emery, carborundum orany. other sultable abradant; Secured to the-motor'shaft -10 so to rotate therewith is a pulley 11 which is relatively "large and connected by a belt 12 "with-the pulley 131011 the grinding wheel shaft 8. Vhen the motor operates the grinding wheel will :be rotated at a highspeed. Extending upwardly from the base member directly-in front of the parallel with the plan'e "of rotationlof the wheel 9 and which] preferably lies" in the plane of the center-of the wheel. The lug 15 has a threaded opening 17'Wl1os'e axis is in:

line with the axisof the opening 16. A j

threaded tubular member 18 has a hand wheel 19 secured to'one end and cooperates with the threads on the alls of the opening 17 so' that H i when it is rotatedit will move towards or away from'the lug 1 1, as the case might be.

A pivot or shaft 20{ has one end provided with a cylindrical part 21 that, fits into the opening in member 18 and extends entirely through this member in the manner shown in Fig. 4; The other end of 'sh'aft20, which has been designated by numeral 22, is some what larger in diameter 'than thepart 21"and has an axial opening 23. The tubular 'end 22 ext-ends into-theopening 16. :A' spring 25 has one end abutting the bottom of the opening 23 and'the other the bottom of the open-'' ing 16. This spring isunder compression andproduces a force which tends to hold the shoulder 26 in contactwith the inner end of the screw 18. It is'now evident th'atby roed in the direction of its axis. The screw 18 moves the shaft 20 positively in one direction and the spring 25'returns it. Directly underneath the shaft 20, the base 5 has an opening 27 whose function will hereinafter appear. An arm 28 has a hub portion 29 that is provided with an opening of the proper diameter to receive the tubular part 22 and is clamped in position on the latter by means of the set screws 30. The length of the hub 29 is less than the distance between the adja'cent surfac'es' of the lugs 14 and 15 and may therefore be moved. in one-direction or the other until its ends come into contact with the adjacent surface of one of the lugs 14 or 15. An arm 31 extends downwardly from the under sideofa hub and terminates within the opening 27. A screw 32 extends through a threaded opening in this arm and serves as Whose upper. surface is plane. A stud 34 projects upwardly from the part 33 and extends perdendicularly with the upper surface thereof. Apart that may be termed a turret head has a base 35, the lower side of which has a plane surface 36 that is adapted to rest upon the plane upper surface of the part 33.

i The part designated by numeral has an upwardly extending arm 37 whose upper end is provided with an opening 38 for the reception of abushing 39. The arm 37 is integral with a U-shaped wall 40 which terminates in .an upwardly extending, portion 41 having a bearing that corresponds to the upper end bearing 42 of the arm 37 and has an opening 43 for the reception of a bushing 44 which corresponds to the bushing 39. A tubular journal or chuck 45 is rotatably mounted in the bushings 39 and 44. The

chuck 45 is also provided with a longitudinal slot 46 within which is located a bowed spring 47 whose curvatureis such that it extends into theinterior of the chuck 45 in the manner shown in Fig. 5. A. pulley 48 is secured tothe tubular member 4.5-by means of a set'screw 49 in the manner shown in Fig. 4. The length of the hub pulley 48 vide as many different chuck members like is the same as the distance between the adjacent surfaces of the parts 41 and 42 so that r it holds the tubular. journal 45 against longitudinal movement.

In Fig. 4 I have shown a valve tappet in place in the tubular rotatable member 45. Vhen the tappet is in place the spring 47 will exertpressure against its outer surface and thereby produce sufiicient friction to prevent it from rotating relative to the member 45. As this machine is intended for grinding tappets for all makes of cars and as these are madein several difierent sizes, it is necessary to prothat shown in Fig. 5 as may be necessary to take, care of the different sizes ofta'ppets. The difference between the several tubular chuekniembers 45' is merely in the internal.

diameter, which must be suitable for the tappet to be ground. The arm 28 has an opening 51 that forms a bearing for a shaft 52 to opposite ends ofwhich pulleys 53 and 54 (Fig. 2) are connected. A belt 55 connects the pulley 53 with the pulley 56 on the drive shaft 10, while a similar belt 57 serves to transmit motion from the pulley 54 to the pulley 48. A handle 58 is secured to the bottom portion of the bearing mem-- ber 41,.in the manner shown in Fig. 3, and is used for rotating the part 35- on the part and for rocking the parts about the axis of the shaft 20. It will be observed that the turn table pivot st'ud'34 is located substantial-ly at the intersection of the central plane of'the pulley 54 with the central plane of the pulley 48 which drives the work holding chuck 45, whereby adjustment may be made without unshipping the belt.

WVhen a tappet face, like that indicated by numeral 59, is to be ground the tappet stem 50 is inserted into the opening in member 45 so as to assume the position shown in Fig. 4. By means of the hand wheel 19, the parts can be moved towards or away from the periphery of the grinding disk 9.

If the disk is to be ground perfectly flat the parts are so adjusted, by rotation about the pivot 34, that the axis of the tappet 50 lies parallel to in the same plane with the axis of the shaft 20. If, however, the surface 59 is to be'made slightly convex, as is often desirable, the axis. of the tappet is placed at an angle with the axis of the shaft 20 about which it rocks. When so placedthe face of the tappet would be ground to a conical shape were it not for the rocking movement, of the-support whereby the-tappet is oscillatedacrossthe. central plane of the grinding wheel whereby the contact point.

at the end of the stroke'is brought a little closer to the margin of the tappethead than it is at the center of the stroke when in a horizontal plane through the axis of the grinding wheel. The part 35 is held in adjusted position with respect tothe. part 33 by means of a clam 60. After the parts 35 and 33 have been properly adjusted, the

which this machine is to be used, the axis of the tappet when at its maximum height above the axis of oscillation must be at the same vertical height as the axisof'the'shaft 8 all as shownin Fig. .4. The fact that the surface to be ground'is rotated during the grinding operation makesit perfectly true and even.

I provided.

pole S on the other.

It is also possible to employ this machine for the grinding of flat objects such as shims, washers and the like. In order to be able to hold these objects, while they arerotated in contact with the grinding surface of the rotating disk 9, a magnetic chuck has been This chuck has been shown in Figs. 6 and 7 as consisting of a round steel disk 61 that is rigidly and nonrotatably connected with the cylindrical stem or shank 62 which is adapted to be inserted into the interior of the rotatable tubular sleeve or chuck 45. The stem 62 has a longitudinal slot or groove'63 with which the spring't'? engages so as to lock the stem 62 and attached disk 61 against rotation relative to the chuck 45. The disk 61 is made of hardened steel of'large magnetic retentivityand magnetized so as to have a north pole N on one side and a south A-groove 6% extends diametrically across the disk intermediate the poles so as to coincide with the neutral axis of the disk when considered as a magnet. It is evident that the electromagnet just described, will hold light objects of iron or steel, such as shims, 65 which have been indicated by dotted lines in Figs. 6 and 7. The disk 61 has been. provided with a plurality of holes 66 for the reception of pins 67 These pins engage-the shims or other objects that are, to be ground,

somewhat in the manner shown in Fig. 7, and

prevents them from sliding along'the surface of the chuck while being ground. Thin fiat objectsmay by this means be ground with great exactness to any thickness desired. Although I have shown shims as being the ob 'jectsto be secured to the magnetic chuck, it

is, of course, evident that any flat object of any shape may be ground and it is also possible to secure piston rings to the chuck so as to grind them to any thickness desired.

aving now described the invention what I claim as new is: V

1. A machine for grinding Valve t-appets and the like," comprising, in combination, a rotatable grinding disk, an oscillatory ar1n mounted for oscillation in continuous reciprocation during grinding operations about an axis that lies in the plane of rotation of the grinding disk and below'the axis of rotation thereof, means for limiting the range and adjustably determining the field of reciprocation, a turret head carried by said arm, said head being mounted so as to berotatable about an axis that is parallel with the axis of the arm, tubular work holding chuck'membel plane of rotation-of the wheel during grinda plane of rotation of the wheel.

3. In a valve grindingmachine, a rotatable grinding wheel, an arm freely oscillatable continuously during grinding operations about, an axis disposed substantially inv a plane of rotation of the grinding wheel,a holder for a valve stem carried by'the arm and movable about an axis disposed in a plane 'parallelto the plane of rotation of the wheel and normal to the axis of oscillation of the arm,'a chuck for a valve carried byfsaid holder, and rotatable about an axis which may by movement of the holder be disposed substantially parallel toor slightly ,angularly rela-:

tive to the plane ofrotation of the wheel, said chuck axis being also disposed in an arcof oscillation about the axis of said arm substantially coinciding with a plane parallel to the axis of said arm and disposed inthe axis of the wheel.-

In testimony whereof I afiix my signature. I HARRY G. MILLER.

mounted for rotation in said turret and com- 1 mon means for driving said tubular member rotatable grinding. 'wheeland a work supporting arm oscillatable continuously across the 

